Electrode clamp



Nov. 7, 1939. R. R. JONES E'LEGTRODE CLAMP Filed OCL. 8, 1958 2 Sheecs-Sheetl l www //WM R. R. JONES ELECTRODE CLAMP Nov. 7, `1939.

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Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE ELECTRODE CLAMP poration of Ohio Application October 8, 1938, Serial No. 234,010

Claims.

The invention relates to clamps or holders such as are used for supporting an upright electrode in an electric furnace and more particul larly to a hydraulic release for the tension bolt I of such a clamp or holder.

The electrodes of an electric arc furnace are carbon or graphite bars and may be of any desired shape of cross section, such as round, square or rectangular; each composed of one or more i pieces clamped or cemented together or of carbon paste compacted into a metal form. Usually the electrodes of round cross section are capable of being joined end toend by methods common to the art. A furnace may contain one or more electrodes and the following description is applied to but one of these usually identical assemblies.

To support this electrode in upright position over a furnace, a common method is to use some sort of a circumferential clamping device, to which is attached the means for supporting it and the electrode from a winch or other adjusting means which is in turn supported by a stationary part of the furnace assembly.

The mechanical and electrical contact with the electrode is generally made by means of conducting pads, usually Water cooled, which are pressed against the electrode on one or more sides, if the electrode is square or rectangular, or segmentally, if the electrode is of circular cross section, by the pr-essure exerted by the clamping device; the pressure being sufficient to ensure a good electrical contact and to prevent the electrode from moving under the influence of gravity.

As the electrode is consumed it is necessary that the relative position of the clamping device and the electrode be changed in order that the conducting pads be maintained in the most eicient position, which is near the furnace roof or the top of the charge.

To cause the clamping pressure to be exerted and released at will and to allow for unavoidable variations in the size of the electrode, a common practice is to use a bolt and nut as part of the assembly, the bolt being in tension. The adjustment of this tension bolt by hand, located as it is, adjacent to the furnace, is a hot, laborious and dangerous operation.

50 The object of this invention is to provide a bolt that may be substituted for the bolt-nut-manually operated type, retaining all the advantages of this type and in addition, aordng means for operating it and slipping the electrode from a distance, by means of hydraulic or air pressure,

to simulate hand operation. Springs in the head of the bolt serve to maintain the parts in a normally clamped position, readily released by pressure.

The above object together with others which 5 will be apparent from the drawings and following description, or which may be later referred to may be attained by constructing the improved clamp in the manner illustrated in the accompanying drawings. The arrangement of tension bolt, clamps, pads and electrode shown in the drawings and referred to in the description, is but one oi the many arrangements that may be used. My invention covers all arrangements wherever tension bolts are used in the assembly. 5

In the accompanying drawings:

Figure 1 is a plan View of an electrode clamp embodying the invention, parts being broken away for the purpose of illustration;

Fig. 2, an enlarged longitudinal sectional view through the improved clamping head with hydraulic release, showing the same in the clamped position; and

Fig. 3, a View similar to Fig. 2 showing the head in the released position of the clamp.

Similar numerals refer to similar throughout the drawings.

The holder or clamp comprises the two spaced clamp members indicated at I0 which are preferably water cooled by any suitable method, and each of which carries a pad II adapted to contact with opposite sides of an electrode I2.

The particular construction of these clamp members does not enter into the present invention and for that reason these clamp members are not illustrated in detail and the means fon water cooling the same is not shown.

The tension bolt I3 is located through the corresponding ends of the clamp members Ill, the head I4 of the bolt abutting one clamp member and the nut I5 being located upon the other end of the bolt for drawing these ends of the clamp members toward each other, or this tension bolt I3 may be a hinged joint or suitable arrangement, or may be replaced in this construction by a duplicate of tension bolt I6 and its assembly.

The opposite ends of the clamp members I0 are arranged to be drawn toward each other by a tension bolt I6 having a nut I'I at one end, and to the other end is connected the improved clamping head with hydraulic release to which the invention pertains which is indicated generally at I8.

This clamping head may comprise the base indicated generally at I9 and the housing 20 which parts Cil is connected thereto by a water tight joint preferably formed by internally threading the inner open end portion of the housing so as to t upon the threaded reduced portion 2l of the base, the end of the housing tting into an annular groove 22 Within the base, within which is preferably located a gasket 23. If desired, this joint may be made to provide a water tight joint which will withstand high pressure by other mechanical means. The base lg'has the ball or rolled end 24 adapted to be seated within a concave socket 25 in the adjacent clamp member I0.

Within the extension 2l of the base is located one end of a hollow cylinder 28 which may be connected thereto in any suitable manner. The

piston 21 is mounted for movement within said cylinder and has located around its periphery the packing ring 28 which provides a water tight sliding rit within the cylinder and which is held in place as by the retainingring 29, which may be connected to the piston as by screws 3U.

The piston rod 3i may be threaded upon its outer end as at 32 for connection to the piston 21 and its inner end may be reduced and threadedy as at 33 for connection to the tension bolt i6, or tension rod 3l can be extended or lengthened to form the tension bolt, I6.

A spring mechanism is located within the cylinder 28 between the base i9 and the piston 2l and surrounding the piston rod 3i. This spring may be in the form of a plurality of saucer-shaped spring disks 34 arranged in opposed pairs as best shown in Fig. 2, but other types of spring may be used.

It is common practice to water cool these clamps or holders and in carrying out the present invention the tension bolt i6 has a central bore 3'! through which may be passed cooling fluid as well as iluid under pressure for providing a hydraulic release as will be later described.

The base I9 has an annular chamber 38 communicating with a cold water inlet 39 and communicating through the passages 40 with the interior of the housing 2%).

The piston rod 3l has the central bore 42 which communicates with the interior of the housing 2i! and with the bore 3l in the tension bolt l5 so that cooling water entering the chamber 38 will pass around the same and through the passages il to the interior of the housing 2i] and will then pass through the piston rod Si an-d ten- Sion bolt I6 to the outlet pipe 43.

A Valve 4d controls the inlet pipe 3S, and a valve 45 controls the outlet. A branch pipe d6 communicates with the pipe 43 and leads to a high pressure hydraulic pump or the like, the valve 4l being interposed between said pump and the pipe 43.

When the head is assembled it is so adjusted that the spring disks 34 will draw the tension bolt l5 to the left as viewed in the drawings, tightly clamping the pads ll of the clamp members lll upon opposite sides of the electrode l2 so as to support the electrode by the holder.

In the normal operation of the holder the valve 4l is closed while the valves de and d5 are open permitting a continuous circulation of the cooling water around the head and through the tension bolt l5 to the outlet.

When it is desired to open the clamp so as to permit the electrode to be lowered relative thereto, the inlet valve 44 and outlet valve l5 are both closed and the high pressure Valve l? is opened permitting the high pressure fluid to pass through the tension bolt I E and piston rod 3l into the housing 20 of the clamping head, and as the pressure builds up, the piston 21 will be forced to the right (Fig. 3) collapsing the spring disk 34, and moving the nut I'I of the tension bolt I6 to the right so as to permit the corresponding ends of the clamping members Il) to move out from each other releasing the electrode l2 from the clamping action of the pad Il and permitting the electrode to be adjusted relative to the holder.

When the desired adjustment is obtained the high pressure valve 4l is closed and the outlet valve 45 is opened permitting the high pressure uuid to exhaust from the clamping head so that the springs 34 may pull the piston back to the clamping position as shown in Fig. 2, and the inlet valve 44 is opened permitting, cooling water to again circulate in the clamping head and tension bolt.

I claim:

1. In combination with an electrode holder including clamp members and a tension bolt located through said clamp members, a nut upon one end of the tension bolt engaging the outer side of one clamp member, a clamping head slidable upon the other end of the bolt engaging the outer side of the other clamp member, a piston within said clamping head, a piston rod connected at opposite ends to the piston and to the tension bolt, spring means cri-operating with the piston for normally urging the clamping head against the adjacent clamp member for clamping the clamp members upon an interposed electrode, and means for circulating fluid through the clamping head and means for building up the pressure of the uid to act against the piston for releasing the spring means.

2. In combination with an electrode holder including clamp members and a hollow tension bolt l located through said clamp members, a nut upon one end of the tension bolt engaging the outer side of one clamp member, a clamping head slidable upon the other end of the bolt engaging the outer side of the other clamp member, 1

a piston within said clamping head, a hollow piston rod connected at opposite ends to the piston and to the tension bolt, spring means cooperating with the piston for normally urging the clamping head against the adjacent clamp member for clamping the clamp members upon an interposed electrode, means for circulating cooling fluidthrough the clamping head, and means for admitting high pressure fluid to the clamping head to act against the pistonfor releasing the spring means.

3. In combination with an electrode holder including clamp members and a hollow tension bolt located through said clamp members, a nut upon one end of the tension bolt engaging the outer side of one clamp member, a clamping head slidable upon the other end of the bolt engaging the outlet side of the other clamp member, a piston within said head, a hollow piston rod connected at opposite ends to the piston and the bolt, spring means co-operating with the piston for normally urging the clamping head against the adjacent clamp member for clamping the clamp members upon an interposed electrode,

means for admitting cooling uid to the bolt and clamping head, and means for admitting hydraulic pressure fluid through said hollow bolt to the clamping head and against the piston to release the spring means.

4. In combination with an electrode holder including clamp members and a tension bolt located through sai-d clamp members, a nut upon one end of the tension bolt engaging the outer side of one clamp member, a hollow clamping head slidable upon the other end of the tension bolt engaging the outer side of the other clamp member, a cylinder within said hollow clamping head and spaced from the walls thereof, a piston within said cylinder, a piston rod connected at opposite ends to the piston and the tension bolt, spring means cooperating with the piston for normally urging the clamping head against the adjacent clamp member for clamping the clamp members upon an interposed electrode, means for admitting cooling fluid to the head and around said cylinder, and means for admitting hydraulic pressure uid to the head and against the outer side of the piston to release the spring means.

5. In combination with an electrode holder including clamp members and a hollow tension bolt located through said clamp members, a nut upon one end of the tension bolt engaging the outer side of one clamp member, a hollow clamping head sldahle upon the. other end of the tension bolt engaging the outer side of the other slamp member, a cylinder within said hollow clamping head and spaced from the walls thereof, a piston Within said cylinder, a hollow piston rod connected at opposite ends to the piston and the tension bolt, spring means cooperating with the piston for normally urging the clamping head against the adjacent clamp member for Clamping the clamp members upon an interposed electrode, ror admitting cooling fluid to the bolt and clamping head, and means for admitting hydraulic pressure fluid through said hollow bolt to the clamping head and against the piston to release the spring means.

ROBERT R. JONES. 

